diff options
Diffstat (limited to 'libc/sysdeps/linux/or1k/fpu_control.h')
| -rw-r--r-- | libc/sysdeps/linux/or1k/fpu_control.h | 88 | 
1 files changed, 88 insertions, 0 deletions
| diff --git a/libc/sysdeps/linux/or1k/fpu_control.h b/libc/sysdeps/linux/or1k/fpu_control.h new file mode 100644 index 000000000..9abde4f42 --- /dev/null +++ b/libc/sysdeps/linux/or1k/fpu_control.h @@ -0,0 +1,88 @@ +/* FPU control word bits.  OpenRISC version. +   Copyright (C) 2024-2025 Free Software Foundation, Inc. + +   The GNU C Library is free software; you can redistribute it and/or +   modify it under the terms of the GNU Lesser General Public +   License as published by the Free Software Foundation; either +   version 2.1 of the License, or (at your option) any later version. + +   The GNU C Library is distributed in the hope that it will be useful, +   but WITHOUT ANY WARRANTY; without even the implied warranty of +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU +   Lesser General Public License for more details. + +   You should have received a copy of the GNU Lesser General Public +   License along with the GNU C Library.  If not, see +   <https://www.gnu.org/licenses/>.  */ + +#ifndef _FPU_CONTROL_H +#define _FPU_CONTROL_H + +#ifndef __or1k_hard_float__ + +# define _FPU_RESERVED 0xffffffff +# define _FPU_DEFAULT  0x00000000 +# define _FPU_GETCW(cw) (cw) = 0 +# define _FPU_SETCW(cw) (void) (cw) + +#else /* __or1k_hard_float__ */ + +/* Layout of FPCSR: + +   The bits of the FPCSR are defined as follows, this should help +   explain how the masks below have come to be. + +   +-----------+----------------------------+-----+----+ +   |  32 - 12  | 11 10  9  8  7  6  5  4  3 | 2-1 |  0 | +   +-----------+----------------------------+-----+----+ +   |  Reserved | DZ IN IV IX  Z QN SN UN OV | RM  | EE | +   +-----------+----------------------------+-----+----+ + +   Exception flags: + +     DZ - divide by zero flag. +     IN - infinite flag. +     IV - invalid flag. +     IX - inexact flag. +      Z - zero flag. +     QN - qnan flag. +     SN - snan flag. +     UN - underflow flag. +     OV - overflow flag. + +   Rounding modes: + +   The FPCSR bits 2-1 labeled above as RM specify the rounding mode. + +     00 - round to nearest +     01 - round to zero +     10 - round to positive infinity +     11 - round to negative infinity + +   Enabling exceptions: + +     EE - set to enable FPU exceptions. + + */ + +# define _FPU_RESERVED 0xfffff000 +/* Default: rounding to nearest with exceptions disabled.  */ +# define _FPU_DEFAULT  0 +/* IEEE: Same as above with exceptions enabled.  */ +# define _FPU_IEEE     (_FPU_DEFAULT | 1) + +# define _FPU_FPCSR_RM_MASK (0x3 << 1) + +/* Macros for accessing the hardware control word.  */ +# define _FPU_GETCW(cw) __asm__ volatile ("l.mfspr %0,r0,20" : "=r" (cw)) +# define _FPU_SETCW(cw) __asm__ volatile ("l.mtspr r0,%0,20" : : "r" (cw)) + +#endif /* __or1k_hard_float__ */ + +/* Type of the control word.  */ +typedef unsigned int fpu_control_t; + +/* Default control word set at startup.  */ +extern fpu_control_t __fpu_control; + +#endif	/* fpu_control.h */ | 
